The prior art has disclosed many methods and apparatuses which serve to improve eye operations and, in particular, the insertion of intraocular lenses (IOLs) into eyes. Thus, methods in which a clouded natural lens of the eye of a patient is removed by surgery and replaced by an artificial lens (in particular an intraocular lens, IOL) are known.
Likewise, procedures in which a further lens is inserted in addition to the still present natural lens of the eye in order to improve the visual acuity of the eye are also known. A large number of very different intraocular lenses are commercially available. Hence, a problem always arising in such operations is that of selecting a suitable type of intraocular lens from different types. By way of example, these available intraocular lenses differ in respect of the refractive index thereof, the employed lens material, the radii of curvature of the lens surfaces, an axial distance between the lens surfaces, the type of haptics, the diameter and further properties.
Furthermore, different types of intraocular lenses also exist, for example intraocular lenses with aspherical lens surfaces or lens surfaces which are free-form surfaces without rotational symmetry. Additionally, intraocular lenses with different zones or intraocular lenses with diffractively optical elements are also known.
To ensure that a suitable IOL is inserted into a patient, it is possible to select an IOL with appropriate refractive power in advance in the case of a patient eye in a phakic state in order thus to achieve a post-surgical target refraction desired by the patient. In this procedure, the post-surgical position, in particular, of the IOL is predicted, in particular depending on a measured capsular bag position. The predictions may be used for improved positioning and centering of the implanted IOL. Alternatively, a surgeon may be assisted in the decision as to whether the implanted lens should be replaced by an IOL fitting into the patient eye in an improved manner.
What should be noted here is that the IOL is initially implanted and the eyesight of the eye is subsequently assessed—still during the operation. In these cases, it may be necessary to replace the IOL if a desired target refraction of the patient eye after surgery cannot be achieved with the refractive power of the implanted IOL. Such a replacement of the IOL is connected with increased complexity during a cataract operation. Moreover, this may also be accompanied by medical complications. Hence, this described method is quality control to the extent of whether an already selected IOL also leads to the desired target refraction.